I read a bit of bad news for all of us Aussies today. Indonesia is to take purchase of 2 SU-27's and 2 SU-30's, the first of a possible 24 of each type to be bought. Apparently this puts our upgraded F/A-18 force 4th in quality, behind Singapore and Malaysia(fortunately both allies), and Indonesia, in our immediate region. The Hornet's are also suffering centre barrel fatigue, which means that training hours are being limited to preserve the airframes. To make it worse, the Indonesians are looking at buying S-300's and an intergrated air-defence system, which seriously degrades the deterrant posed by our F-111's and their AGM-142's.
While the current Indonesian government is relitively friendly, their are lots of Generals who are pissed off about our involvement in the liberation of East Timor. If their were a coup, it could spell trouble for us. I don't see that our government has any choice but to upgrade our airforce, to get us through the next 10 years before the JSF can be expected to arrive. Possible options are,
-Leasing/buying new fighters until the JSF arrives. The late model F-16's would solve the fatigue problems of the F-18's, but would not give a real advantage over the SU-27.
-An F-18E/EF-18G combo would be formidable, with the EW aircraft giving us a real advantage, though I don't like the idea of the "E's" getting caught without the "G's". This plan would however have training/maintainance advantages, as we already use F-18's.
-A "silver bullet" force of F-22's has been suggested as part of the JSF buy, to give us a clear air to air advantage over any adversary. The government has rejected this, but mabye the idea or a variation of it needs to be introduced to get us through the next few years. While the F-22 may be to expensive/not available to Australia, a squadron of Typhoon's, to replace the oldest F-18's, may give us the edge we need. The F-18's could then be kept in reserve and rotated through the remaining squadrons, to extend the life of the force and give the pilots the hours they need. This would also give us an independent ability to provide dissimilar air combat training, though it would introduce another completely different logistics train.
-ALCM's like the Joint Standoff Weapon for the F-111's, outranging the S-300s would provide us with the deterrant we need. They would also mean the F-111's could continue to adopt the less demanding high-level approach.
-Long-range missile defences(ie, Patriots), for our northern facilites and for Darwin has also been suggested.
Any thoughts on this?

Well If they use them right, they could be a problem.
First of all: Force the enemy to fly low - as the fuel will be used up. Then prepare to catch them low down - which a hell of a proposition. for example Tornado low (100 feet) going full military power is one slippery costoumer.
Buy or borrow some F-18 or F-16 with AMRAAM.
Get Patriot
Get Stinger
Get guns with Flycatcher.
Get an observer corps.
Tactics:
Attack early on with fighters. The aim is to split up formations, and force the enemy to go into burner.
In front and in killing zone:
Observers teams of 4 to a density of 1 team pr. 400 km square. mobile on jeeps with radio/telephone.
Integrate the radar picture with the observer picture. Shoudn't be too diffcult with under 100 targets at any one time.
Observer primary task: Observe and report.
Observer team secondary task: Fire at opportunity.
The killing zone:
Fighters with AMRAAM and sidewinder-type PLUS
Patriot PLUS guns PLUS Stingers.
This will raise the hair of the pilots; but a concentrated fire like that should make most of the enemies very tired.
It can be done without too much risk of freindly fire - PROVIDED THE TRIGGER HAPPY KNOW THEIR AIRCRAFT RECOGNITION - rather a grandmother with bifocals and aircraft recognition, than heroes of the SAS-Squadron without either.
After killing zone: Fighters to sweep up the sorry remnants.

Bad news indeed.
The news today that they needed to trade palm-oil and the like is both reassuring (they can't buy a lot) and disturbing (the Russians will sell to you even if you can't raise the cash).
It is becoming increasingly clear that an interim fighter is going to be required before the arrival of the F-35 if the RAAF pilots are to maintain their operational readiness.
F-16s are the most likely candidate. As to the F-18 I would have thought that this would be very attractive to the RAAF given the advantages you mentioned. The F-22 is very attractive in any case. However, and I suspect that Australia could buy a small number if we so wished - ie. the US would sell them to us - I doubt that we would do so due to the cost.
This leaves us in an invidious position of being equally matched (though it is very unlikely that we will be outnumbered...this could depend on how much palm oil the Russians want!) when we have generally relied on a technological advantage - but, as you said, this couldn't last!
ALCMs must be purchased - and some form of cruise missile for the Collins class.
On the subject of SAMs I was disappointed but not surprised to here that Rapier is to be replaced by additional RBS-70s. I had hoped that it would be replaced by a more powerful/longer ranged/more advanced missile but unfortunately that is not to be. I feel that this was an opportunity to significantly add to the army's air defence and that it has sadly been missed.
Patriot - would this be the best system to buy? It appears to still have a lot of problems - are there good alternatives?
Maybe we could get s-300 - surely the Russians would be intereseted in some fine wool and top grade wheat?

It looks like the government will be looking for some interim type for the F-111, which is increasingly looking to be replaced in about 2006. I'd personally go for 48 leased F-18E's and 12 EF-18G's, with JASSM's, 2000lb and 500lb JADM's and HARM (also to equip the F-18A's), to replace the F-111 and supplement the F-18A's. The F-18E's have adequate range to attack Indonesia, expecially with JASSM's and can provide fighter escorts. The F-18A's can be used to defend (air to air and air to surface) closer to home.
An all multi-role force is far more flexible than the current arrangement, giving us about a 2 to 1 numbers advantage if we use all aircraft in fighter configuration, in the worst case scenario war against Indonesia. The use of F-18E's as fighters will also allow the F-18A's to be rotated through training, therefore conserving airframe life. Finally, the use of EF-18E jammers would give us a big advantage over an enemy using SU-27's, which can otherwise be considered to be better fighters than any of the F-18's.

On the RBS-70 purchase, yes I agree that a longer range system would be better. I personally like the USMC's new AMRAAM based SAM system. However, extra RBS-70's, with associated radars, are better than the Rapiers we had. They are far more mobile and are completely un-jammable, for only a 1 km range disadvantage.
I think a long-range system like the Patriot is un-justified at this stage, as it is an overkill for most aircraft and our risk of ballistic missile attack is still low at this stage. Better to see how the threat develops, and to get the latest model, rather than spend a lot on something of limited utility now.

The fit of such a lease with your initial post in this thread for an interim fighter to take the load off the F-18As is noted. You would have the As in operation as is up until the arrival of the JSF?
The As could be phased out as the 35s are phased in with the lease on the Es & Gs running until the F-35 force was at full operational status.
The 2-1 numbers advantage would also be enourmously enhanced once the (minimal number of) AEW&C planes are delivered. The new tankers would also greatly enhane the strike capability of any such force.

Was the RBSS-70 evaluated against the latest version of the Rapier, the JERNAS/RAPIER FSC. Surely all other things being equal, it would have made sense to stick with a known system, albeit much upgraded?

That would leave Australia's air defences in pretty good shape:
F-18
Jindalee
AEW&C
RBS-70
I leave the gap deliberately - in terms of Thomas's layered approach to air defence the lack of a medium to long range air defence missile is striking.
I have skipped Thomas's F-22 suggestion - that, unfortunately, is just not going to happen due to the cost!
From a strike perspective it would also leave Australia in an good position - particularly with the acquisition of JSSM/Cruise.